Personal watercraft are small self-propelled boats that are used by one or two people. One such type of personal watercraft are jet skis. Jet skis, which are propelled by jets of water, are equipped with water pumps for propulsion. When a jet ski is not in use, it is desirable to store it out of the water. Because the water pump and impeller can pick up debris if the jet ski is parked on a beach, it is desirable to store the jet ski on a dock or cradle.
Jet skis are very heavy, weighing between 230-450 pounds. Therefore, some sort of lifting apparatus is needed to lift the jet ski up onto a dock (and to lower the jet ski into the water). Various prior art dock lifts have been employed to lift small boats and jet skis up out of the water. They all suffer from the disadvantage of being unable to move the load onto the dock. Instead, the prior art dock lifts merely lift the load up out of the water; the load is positioned out over the water and not over the dock. This is disadvantageous because jet skis must be removed from the lift to be stored. Because jet skis are heavy, they are difficult to move horizontally from a position out over the water onto the dock. Furthermore, servicing the jet ski while it is located out over the water on prior art boat lifts is clumsy and difficult; the operator must lean out from the dock over the water. Unlike large boats, jet skis are too small to climb on board for some types of servicing; servicing is better performed when not on board the jet ski.
Thus, it is desirable to have a boat lift apparatus that not only raises the load out of the water to a desired vertical height, but also can move the load horizontally over the dock. The prior art boat lifts appear to be limited in their directional lifting capability by their mounting arrangements to a load-bearing structure such as the bottom of the water body or the adjacent dock structure. These mounting arrangements prevent movement of the load from a position over the water to a position over the dock.
The problems with the prior art boat lifts are alleviated somewhat by installing the lift on an inside corner of a boat dock, so that the lift is bounded by the dock on two sides. However, with such an arrangement, the load must still be moved from a position over the water onto the dock. Furthermore, many docks do not have such an inside corner.
In addition to having a boat lift apparatus that moves the load both vertically and horizontally, it is desirable to have a lifting system that would eliminate manual lifting of a jet ski on and off of the lift apparatus. This is because there are many situations in which the jet ski must be loaded on and off of the lift apparatus. For instance, the jet ski may be stowed in a location (such as a garage or house) away from the lift apparatus. Or, several jet skis may utilize a single lift apparatus, thus necessitating some shuffling around of jet skis.
In the prior art, there are small wheeled carts which support jet skis off of the ground and also allow the jet ski to be easily moved from place to place. When transferring the jet ski from its cart to any type of lift apparatus, the jet ski is manually picked up off of the cart and then placed onto the lift. After use, the jet ski is transferred back to the cart by manually picking it up off of the lift and placing it onto the cart. This frees the lift for other jet skis. The loaded jet ski can then be wheeled back to its storage location. It is therefore desirable to eliminate this manual lifting of the jet ski when transferring it between the cart and the lift.